1. Field of the Invention
The present invention relates to a magnetic recording medium and a method of manufacturing a magnetic recording medium.
2. Description of the Related Art
Conventionally, magnetic recording media such as a hard disc have magnetic layer which is sectioned into a plurality of data areas and a plurality of servo areas for information recording. Servo information intended for control such as head positioning is magnetically recorded on the servo areas in a predetermined servo pattern.
The process of recording the servo information has a problem of low productivity since servo pattern parts of the servo areas and the peripheral parts thereof are magnetized in opposite polarities one by one for every magnetic recording medium by a servo track writing method. In particular, with a recent improvement in surface recording density and an accompanying decrease in head flying height, high-density high-precision recording has also been required of the servo information. This means an increasing need for an improvement to the recording efficiency of the servo information.
In view of this, there have been proposed magnetic recording media in which the magnetic layer is formed only in either ones of the servo pattern parts and the peripheral parts so that a servo pattern is formed physically (for example, see Japanese Patent Laid-Open Publication No. H 6-195907). In this case, a direct-current magnetic field can be uniformly applied to the magnetic recording medium to magnetize the magnetic layer to the servo pattern, with a significant improvement in the recording efficiency of the servo information.
Nevertheless, when the magnetic layer is formed only in either ones of the servo pattern parts and the peripheral parts, it is either the servo pattern parts or the peripheral parts alone that can be magnetized. This produces the problem that the output amplitude shrinks by half or so as compared to conventional magnetic recording media in which the servo pattern parts and the peripheral parts are magnetized in opposite polarities, with a drop in the read accuracy of the servo information.